Plain English Summary

Background and study aimsThe healthy heart contains four valves, whose job it is to ensure that blood flows in the right direction through the heart. If one or more of these valves becomes damaged or diseased, then this can lead to narrowing of major blood vessels in the heart (cardiac stenosis) which block blood flow, which can increase risk of heart attack. Traditionally, the main surgical treatment was to perform major surgery, opening the chest and replacing the diseased valve with a new one. This procedure can be very dangerous however and some people are too unwell to have it performed on them. Transcatheter aortic valve replacement (TAVR) is a type of heart surgery which repairs damaged valves within the heart, without having to remove the old valves. Unlike many other types of heart surgery, this type of procedure does not require the chest being opened, as the procedure can be done through very small openings, such as through the femortal artery (large artery in the groin) or through a small incision (cut) in the chest. It is generally effective however data from a population of 380 patients from the University Hospital of Zurich recorded in the Swiss TAVR registry shows that some patients do not show improvement or can experience worsening of heart function after the procedure. This study is designed to evaluate the mechanisms of this phenomenon by measuring heart function during the TAVR treatment.

Who can participate?Adults with severe cardiac stenosis who are suitable for TAVR.

What does the study involve?After agreeing to take part, participants undergo a clinical examination to check that they are suitable to undergo treatment by TAVR. The surgical procedure is performed using standard techniques and involves the placing of an artificial valve in the heart by a thin tube (catheter) that enters the body through a small cut in the chest or through the main leg artery. During the treatment, heart function is assessed immediately before and after the valve is repaired by special tubes which measure how well the heart is working. Participants are followed up three months later with a range of heart scans to find out if heart function has improved.

What are the possible benefits and risks of participating?There are no direct benefits to participants, however the results of the study might help to improve future patient management after TAVR. There are no notable risks other than the standard risks of complications when undergoing a TAVR.

Where is the study run from? University Hospital of Zurich (Swizerland)

When is the study starting and how long is it expected to run for? September 2016 to October 2017

Who is funding the study?University Hospital of Zurich (Swizerland)

Who is the main contact?1. Professor Francesco Maisano (scientific)francesco.maisano@usz.ch2. Dr Andrea Guidotti (public)andrea.guidotti@usz.ch

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Study hypothesis

Perioperative pressure-volume loop recordings during TAVR will can help us to explain why about 50% of the patients with preoperative LVEF < 40% fail to improve their LVEF postoperatively.

Ethics approval

Cantonal Ethics Committee in Zurich, Switzerland

Study design

Single-centre non-randomised pilot study

Primary study design

Interventional

Secondary study design

Non randomised study

Trial setting

Hospitals

Trial type

Other

Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet

Condition

Aortic stenosis

Intervention

Pre-procedure, all patients will undergo TTE and Cardiac CT according to routine practice, to determine the indications for the procedure and compliance with the inclusion/exclusion criteria of the study. Individuals meeting inclusion criteria will be informed about the REFIT study and after giving their informed consent, their demographic characteristics and medical history will be recorded. Also all other standard examinations prior to TAVR will be performed, including physical examination, EuroScore assessment, clinical status, laboratory tests, medication recordings, ECG. Baseline TTE and cardiac CT will serve to plan the TAVR procedure. The procedure will consist of TAVR with pre- and post-procedural PV-loop recordings under echocardiographic and fluoroscopic guidance. At discharge, clinical status including medication, TEE, ECG and laboratory tests will be recorded as well as adverse events (AE) and documented in the CRF. Within the follow-up examination 3 months after the intervention, patients will be clinically examined and the same examinations will be repeated (TEE, ECG, laboratory testing). Medication and AE’s will be recorded.

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Primary outcome measures

Left ventricular contractility is measured by conductance catheters before and after TAVR.

Secondary outcome measures

1. Indexes of systolic function are derived by Transesophageal Echocardiography (TEE) before and after TAVR2. Ventricular remodeling after the intervention is measured by comparing parameters derived from Transthoracic Echocardiography (TTE) at baseline and 3 months